Agent for improving lubricating oils



Patented Oct. 22, 1940 PATENT. OFFICE 2,218,997 AGENT FOR IMPROVINGLUBRICATING OILS Jones'l. Wass'on, Elizabeth, N. 1., asaignor toStandard Oil Development Company, a corporation of Delaware No Drawing.Application September 15, 1937, Serial No. 163,918

Claims. (01. zed-'13s) The present invention relates to an improvedaddition agent for lubricating oils and to a method for producing saidagent and likewise to a lubrieating oil containing the addition agentbeing 5 adapted for use at high temperature, for example,

as a motor oil by reason of its resistance to oxidation, sludgeformation and other forms of deterioration. This application is a.continuation in part of application No. 758,437, filed December 0 20,1934, issued February 22, 1933 as U. s. Patent 2,108,954 to Jones I.Wasson, on the subject of lubricating compositions. The invention willbe fully understood from the following description.

Motor oils and other lubricants which are sub- 1 jected to elevatedtemperatures showdeterioration by oxidation, sludge formation and thelike.

Such deterioration maybe checked by the additionof certain materials,for example, oxidation inhibitors for reducing the oxidation rate anddispersing agents for preventing or reducing sludge formation. Most ofthese agents useful for one particular purpose are undesirable fromanother point of view. For example, most of the oxidation inhibitorsraise the Sligh value of an oil. In the present case a new additionagent has been preparedwhich has the remarkable ability to check all ofthe various known forms of deterioration and without in any wayinterfering with or diminishing the value of the oil for lubricatingpurposes.

The addition agent which forms the principal feature of the presentinvention is produced from various high boiling unsaturated aliphaticmaterials, among which are cracked paraffin waxes,

heavy unsaturated paraflin wax and long chain olefin compounds.Unsaturated fatty acids and esters may also be employed such as'theglyceryl or glycol esters, monohydric alkyl esters, alcohols and thelike. The above materials are all 40 characterized by long hydrocarbonchains, for example, containing more than 10 carbon atoms.

Such unsaturated raw materials are usually secured by either cracking,dehydrogenation, dehydration or the like of the saturated compound.

The preferred raw material is a cracked wax having more than 10 carbonatoms in the molecule. These materials are then caused to react withsulphur chloride so as to form a product containing both' sulphur andchlorine. The sulphur is believed to be in the form of polysulfide' andis corrosive when tested with a bright copper strip in' the usualmanner, but as will be noted, the subsequent treatment renders thematerial noncorrosive., The reaction with sulphur chloride isaccomplished in the well known way, preferably at ordinary temperaturesand with cooling since heat is evolved. The reaction is not permitted toproceed to such a degree as to produce solid materials but is cut shortwhen the product is still liquid and soluble in mineral oils.Ordinarily, the reaction may be accomplished in 1 to 4 hours at atemperature not above about 300 F. and the reaction may be brought to astop either by a careful control of the amount of sulphur chloride addedor by the addition of alcoholic alkali or other such materials whichdestroythe sulphur chloride.

The intermediate product obtained in the ways outlined aboveis thensteamed, preferably in the presence of alkali so as to remove at least apart of the chlorine and to replace this with hydroxyl groups. verts thecorrosive sulphur to a non-corrosive variety so that the final compoundwill not tarnish copper, The chlorine may be entirely removed but if itis reduced to a small quantity, say less than 5%, results are quitesatisfactory. It will be understood that more chlorine than this may beallowed to remain but it is not particularly advantageous, in fact it isbelieved to be preferable to remove the chlorine to as complete a degreeas possible. The presence of hydroxyl groups is indicated by the acetylvalue.

This treatment also removes or con-- The final product may be purifiedin any desired manner and in the end-consists of an aliphatic hydroxysulfide or polysulfide soluble in mineral lubricating oils and fluid atordinary temperatures.

The'oils to which the above substance may be advantageously added arehigh boiling petroleum fractions, particularly the lubricating oils.produced by ordinary refining methods such as distillation, acid,alkali and/or clay treatment or the more highly refined oils such asproduced by hydrogenation, destructive hydrogenation, heavy acidtreatment or solvent extraction... It has been observed that the morehighly refined oils show a greater tendency toward rapid oxidation andthis is effectively checked by the addition of relatively small amountsof the agents prepared in the manner described above. The amount mayvary considerably with the particular oils but it is usually found that1% more or'less gives satis: factory results.

The addition agents may be added also to high boiling fuels andinsulating oils which are subjected to high temperatures.

As an example of the production of the addition agent and its effects,the following may be considered? 4 Parafiin wax is cracked by heat at810 F. liquid phase and under 50# pressure to give a total .Acetyl valuecracked product boiling from about 200 to 650 F. and about 50 to 60%olefin content.

To 100 parts by weight of the cracked wax is added 10 parts by weight ofsulphur mono-chloride and the temperature is held down below 200 F.during the reaction period of about 1 hour. The product recovered isfiuid,soluble in mineral oils and contains about 2% by weight of each ofthe elements chlorine and sulphur. The intermediate obtained above isthen refluxed or steamed over alcoholic soda for onehalf hour, dried andfinally recovered. It has the following analysis:

Per cent 82.67 14.12 2.07 0.35

To one sample oi a well refined S. A. E. .50 grade lubricating oil isadded 1% of the above agent and the rate of oxidation is determined andcompared with that 01' a blank sample of thesame oil which does notcontain the addition agent.

Carbon- Hydrogen Sulphur- Chlorin Total The test is made by continuouslypassing oxygen through a. 10 cc. sample of oil at a definite ratev whilemaintaining the sample at 200 C. The oxygen is passed through a closedsystem and the amount dissolved is determined by difierence between thevolume originally present and the undissolved oxygen which is measuredat 15 minute intervals. The results are as follows:

Oxidation rate absorbed cc. per m utes Sample 5. A. E. 50 132-116-82-49Same+l% hydroxy sulfide l7-2015-i6 The Sligh values of the above samplesdetermined according to the method given in A.-S. T. M. Report D-2, P.22 (1927)except that the time of heating is 24 hours instead of theusual 2% hours were 6.7 for the blank and 2.2 for the same containingthe addition agent.

Another sample of the addition agent was prepared in the same generalmanner indicated above and when added to a highly refined lubricatingoil of high oxidation rate in proportion of 1% showed an oxidation rateof 3'73828--32. The Sligh value was 1.2, less than of that of theunblended oil.

An additional sample oi aliphatic hydroxy sulfide was prepared in thefollowing manner: 8

parts by volume of sulphur monochloride was added to 100 parts by volumeof a cracked wax secured in the manner as outlined in the above example.This mixture was initially heated at a temperature of from 200 to 225 F.and then the temperature was raised to about 300 F. and the mixturemaintained at 300 F. for approximately amass:

cordance with the above method was added to a standard lubricating oiland the oxidation rate determined with the following results:

In the above description, the agent is described as an-aliphatic hydroxysulfide or polysulfide and by this it is meant that-the hydroxyl andsulphur groups are attached directly to the aliphatic chain. It isdefinitely intended to include under this term materials includingcyclic aromatic or naphthenic rings, which may or may not besubstituted, providing that the sulphur and hydroxyl groups are attacheddirectly to the aliphatic chain as indicated. The oils may be blendedwith other known materials to increase oiliness, thickeners, metallicsoaps, dyes, pour point inhibitors or the like, as in the case of anyother mineral oil.

The present invention is not to be limited by any theory of the methodby which the agents are producedv or any theory of their activity forthe purposes disclosed, but only by the following claims in which it isdesired to claim all novelty inherent in the invention.

I claim: I

1. Process of producing oil soluble aliphatic hydroxy sulfidescomprising treating cracked wax with a sulphur halide at a temperaturenot exceeding 300 F. and refluxing the resulting product with analcoholic alkali.

2. Process in accordance with claim 1 in which said cracked wax has atleast 10 carbon atoms and said sulphur halide is sulphur monochloride.

3. Process for producing oil soluble aliphatic hydroxy sulfidescomprising treating olefin compounds having at least 10 carbon atomswith a sulphur halide at a temperature not exceeding 300 F. andrefluxing the resulting product with an alcoholic alkali.

4. Product prepared in accordance with the process of claim 7.

5. Product prepared in accordance with the I process of claim 1.

6. Product prepared in accordance with the process of claim 3.

7. The process of producing oil-soluble aliphatic hydroxy sulfides whichcomprises subjecting parafiin wax to liquid phase cracking underpressure and at cracking temperatures to form a product containingbetween and 60% of long chain olefins, treating the cracked product withsulfur chloride at a temperature not exceeding 300 F. and refluxing theresulting product with dilute alcoholic alkali. 1

8. Product consisting essentially of an aliphatic hydroxy-sulfide inwhich the hydroxy radical and the sulfur are attached directly to thealiphatic chain.

9. Product according to claim 8 which is soluble in mineral oils and isfluid at ordinary temperatures.

10. Product consisting essentially of an aliphatic hydrocarbon chainhaving directly attached thereto an hydroxy group and a sulfide group,and including a cyclic group selected from the class consisting ofaromatic and naphthenic rings. 0

- JONES- I. WASSON.

